The invention concerns a milk tube for a milking unit with two end regions lying opposite to one another and an intermediate region. Furthermore, the invention concerns a milking machine with milking tubes that are arranged together with teat cup liners in a multiple number of milking cups. Furthermore, the invention concerns a method for the manufacture of a milking cup with a milk tube, whereby a milk tube is connected to a teat cup through fixing means. The invention finds application in the dairy industry and especially in the production of milk.
For the milking of milk-producing animals, milking systems are used that may have different designs. The milking process as such is carried out with the aid of milking cups that are applied to the teats of the animal. A milking cup has a teat cup liner to which reduced pressure and atmospheric pressure is applied, corresponding to a pulsator frequency. For this purpose, the milking cup is connected to a pulsator tube and the milked milk is led away from the milking cups through a milk tube.
Milking systems are known in which each milk tube is connected to a milk collecting piece. For this purpose the milk collecting piece has connecting pieces over which a milk tube is attached in each case. Each of the connecting pieces has an end cut at a slant which facilitates attachment. The milk tube is clamped at the slanted cut edge when the teat cup hangs freely from the milk collecting piece. Such a design of a milking machine is known for example from DE 34 29 428 A1.
Due to the fact that the milk tube is exposed to alternating bending stresses at the slanted cup edge of the milk connecting piece, the tube is subjected to rapid aging and must be replaced more frequently. An essential problem is also that the short milk tubes may become damaged by sudden loads at the slanted cup edge of the connecting piece.
The milk tube is attached to the connecting piece by static friction. If the milk tube is pushed onto soiled surfaces or surfaces with fat on them, then here the friction is reduced. There is a danger that during the milking the milk tube will slide off from the connecting piece. Once the milk tube has slid off the connecting piece, it can hardly ever be remounted onto the connecting piece with safe functioning assured. The friction is essentially determined by the connecting piece/milk tube material pairing, so that the choice of materials is limited.
Another problem, which is not less severe, arises from the design of the tube connection due to the fact that complete cleaning can only be achieved with significant expenditure. Namely, hereby there is a danger that incomplete cleaning occurs, since flow-technological dead areas are formed within the milk tube, so that although the soil may have been separated by a cleaning, it can no longer be removed from the milk tube.
Furthermore it is known that vacuum fluctuations may be caused by the connecting pieces because the cross-section of the tube is changed by the bending. This leads to non-uniform milking processes.
Thus, as a result, it can be said that the systems known in the state of the art are either subject to increased wear and therefore must be replaced at regular intervals, or very thorough cleaning is required, which involves dismantling of the system.